Among other characteristics, separation methods employing membranes are used for separating various gases since such methods boast, among other characteristics, higher energy efficiency while using structurally simpler equipment, than other gas separation methods.
The most common embodiment of a gas separation membrane involves forming a thin film of a gas-separating resin on the surface of a porous support membrane. This embodiment is effective for allowing permeation of substantial amounts of gas while imparting certain strength to the membrane. As the porous support membrane there can be used, for instance, a membrane having a structure of an ultrafiltration membrane, as disclosed in Patent document 1.